Stem-making machine for radiotubes and the like



Dec. 24, 1929. c. EISLER 1,741,016

STEM MAKING MACHINE FOR RADIO TUBES AND THE LIKE Filed April 25,1925

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' Fig.3 F1 4 v Z4 1: 595 62 U J 5/ 2s Z5 6/ ea 49 g ec/ 4 LL fi ni 3/ -42 2 Hi 4 43 8 H 5 s5 4 4/\ 4 f Il/ 41 J H [it E1 7 $9 22 INVENTOR BY kid ATTOR N EY Patented Dec. 24, 1929 UNITED STATES PATENT; OFFICE CHARLES EISLER, OF NEWARK, NEW JERSEY, ASSIGNOR TO EISLER ELECTRIC COB- POBATION, A. CORPORATION OF DELAWARE STEM-MAKING MACHINE FOR RADIOTUBES AND THE LIKE Application filed April 25, 1925. Serial No. 25,746.

This invention relates to machines for making stems for radio tubes and the like, particularly for making stems of the character set forth in my application Serial No. 6,527 filed February 3, 1925. That application is directed to a novel method of making stems for bulbs of the general character set forth in the J aeger Patent #729,182, May 26, 1903 and comprising a stem tube with the leadingin wires sealed to one end thereof and an exhaust tube having one end bent laterally and welded to the side of the tube at a point removed from the sealed end.

The object of the invention generally is a machine whereby the stem parts may be readily and with the desired facility assembled in the proper relation to each other and then automatically formed into unitary stems and without further attention from the operator. A further object of the invention is a machine of this character wherein the operations of sealing the filament wires within and to one end of the stem tube and of fusing and welding the exhaust tubes to the inside of the stem tube are separate and distinct from each other, enabling the performance of such operations at different stations of the machine, if desired. A further object of the invention is the novel correlation of machine parts and mechanisms facilitating the forming of stems of the character above indicated. A still further object of the invention is a machine of the above indicated character having a minimum number of parts and having its mechanisms of simple construction whereby the machine and its parts may be econom ically produced and the operation thereof rendered more reliable.

For a better imderstanding of the above indicated novel features of my invention and others which will hereinafter appear, reference may be had to the accompanying drawings forming a part of this application wherein:

Fig. 1 is a plan view more or less diagrammatic of a machine embodying my invention,

Fig. 2 is a sectional view along the line 2-2 of Fig. 1,

Figs. 3 and 4 are views of a finished'stem,

Fig. 5 is a front View of the stem parts showing their assembled relation before the sealing,

Fig. 6 is an enlarged plan view of an exhaust tube holder,

Fig. 7 is a side View thereof, and v Fig. 8 shows a slightly modified arrangement of burners.

Referring to the drawings where similar numerals designate similar parts throughout,

I have illustrated a stem making machine comprising a table 1 carried by suitable standards, on the upper and lower sides of which are carried the correlated parts of the machine. Revolubly mounted on the table 1 is a main frame or spider 2 with a number of supports (spindles) 40, also mounted for rotation about vertical axes. These spindles 4O successively occupy the positions A, B, C, D, E, F, the particular machine illustrated being a six position machine. This is efiected through intermittent movement of the main frame 2. This intermittent movement is effected by means of a Geneva wheel 11 fixed to the vertical shaft of the spider or frame and the Geneva driver 12 which is connected to the drive shaft 5 through a worm gear 13 and worm 14. The driving shaft 5-may be driven by any source of power, as for example' by. an electrical motor through the spur gears 15 and 16 and intermediate shaft 17 on which is mounted a driving pulley 18 connected by a belt to the motor (not illustrated). At positions A and B the holders or spindles 40 are stationary to provide for the taking off of the completed stem and the assembly of stem parts. At the other positions, namely positions C, D, E, F the spindles are continuously rotated by means of a drive consisting of the rubber drivers 3 which engage the spur gears 4 fixed on the lower ends of the spindle shafts. The rubber drivers 3 are disposed adjacent positions C, D, E and F so as to be engaged by the spur gears 4 when the intermittent rotating frame 2 comes to rest and are mounted on vertical shafts 8 journaled in the table 1. The shafts 8 carry on their lower ends the sprockets 7 around which passes an endless driving chain 6 for continuously rotating the drivers. One of these vertical shafts 8 is provided with a worm gear 9 which meshes with the worm 10 on the shaft 5.

Each of the spindles 40 comprises a pair of stem tube engaging clamps 41, the latter being pivoted at pivotal points 42 and having a pair of gripping parts 43 below the pivotal points 42 for separating the clampingmembers 41 against the tension of the spring 44 for the insertion of stem tubes and the removal of finished stems. These clamps'41 are of standard construction and I have 11- lustrated associated therewith the holder or receptacle for the filaments and wire mounts 45, this holder being indicated at 46. I have 15 also indicated a pair of standard clamping or squeezing members 19 which are operable by means of the vertical actuating rod 47 and the connecting links 48, the rod 47 passing through hollow spindle shafts.

The mechanism for holding and retaining the exhaust tube 49 with its laterally bent end 50 projecting into the flared end of the stem tube 51 and engaging the side wall thereof is indicated in detail in Figs. 6 and 7. It is similar to the mechanism set forth and claimed in my Patent #1,522,001, January 6, 1925. This comprises a vertical support 32 which is oscillatably mounted within openings formed in the brackets 52 formed as a part of the 'spindle frame 38. This support 32 is in the form of a tube and carries on its upper end a clamp member 31. This clamp member 31 is provided near its outer end on one side with an exhaust tube seat 53 with which cooperates a pivoted clamping jaw 26 to clamp an exhaust tube therebetween and hold it with its lower end projecting into the stem tube 51 and with the laterally bent end 50 of the tube engaging the side thereof. This clamping member 26 is pivoted to the outer end of the clamp 31 and is connected on its rearward end by means of links and 29 with a rod 28 passing upwardly through the supporting tube 32 and oscillatably mounted therewithin. The rod 28 is provided with a handle 27 by means of which the operator may rotate the rod 28 to first open the clamps 26 and 31 and by further movement to then rotate the clamps together to the dotted position shown in Fig. 6. When the operator pulls the handle 27 the movable jaw 26 opens until it meets a shoulder on the jaw 31. Then both turn together to the dotted position shown and in this position the parts are automatically held by the steel ball 33 contained within a countersunk hole in the lower bracket 52 and entering a corresponding counter-sunk hole in the tube 32, this ball being held in position by the spring 34. To bring the exhaust tube holder back into the full line position shown, it is only necessary for the operator to apply sufiicient pressure on the handle 27 to kick the ball 33 back against the tension of the spring 34 out of register with the recess in the tube 32, and a torsion spring 35 having one end connected with the rod 28. and the other end to a stationary finger or lu 54 assists returning the clamp to the all line position shown. An adjustable stop or member 36 may be attached to the tube to determine the correct position of the tube 32 and the clamp by coming into contact-with thelug 37.

As above indicated the positions A and B wherein the spindles 40 are stationary are for the removal of the finished stems and the assembly of the stem parts during the stationary periods of the frame 2. Fig. 5 shows the relation in which the stem tube. 51, the mount 45 and the exhaust tube or tubulature 49 are held by the various parts of the rotating spindle when properly'adjusted. This may correspond to either posit-ion A or B of the machine. Assuming it is position B, at the next intermittent movement, the disunited stem parts thus assembled are brought into position 0 whereupon the rubber driver which is continuously rotating 'comes into driving relation with the spur gear 4 and rotates the spindle around the vertical axis. At this point the burners 55 are caused to direct a heating flame adjacent the non-flared end of the exhaust tube 51 and at a point below the laterally bent. exhaust tube 50, the flames there serving to gradually heat up the stem tube 51. At the next intermittent movement the head is carried to position D where more concentrated flames 56 from the burners illustrated, eight. in the particular embodiment shown are caused to finish the fusing and melting of the lower end of the stem tube 51 and after such melting and while the head is still in osition D, the movable squeezing jaws 19 are rought together to squeeze the lower '1 4 end of the tube about the wires and mount 45 into the flat mass 57 shown. This movement of the clamping jaws is efiected through the upward movement of the push rod 58, which, in this position B of the spindle, is in line with and engages the push rod 47. The push rod 58 passes downwardly through the table 1 and. is fastened to one end of the lever 20 while the other end of the lever is-operatively engaged by the cam 21 on the Geneva driver shaft 22, the cam 21 actuating in the proper time relation the lever 20 in the direction of the arrow and against the spring 59 to cause the rod 58 to engage the rod 47 and b upward movement thereof to operate the c amps 19.

When the cam 21 passes the free end of theflame on a line with the end of the laterally bent exhaust tube 50 and at a point substan tially removed from the sealed mass 57.- The flames from the burner 61 serve the purpose of softening the stem tube 51 at this point and welding the laterally bent end of the exhaust tube to the inside side wall thereof. During this operation the nozzles are caused to direct a cooling blast of air within the flared end of the stem tube 51 to prevent the collapse or distortion thereof when these heating flames 61 are playing thereupon. A gage 62 adjustably carried by the rod 28 at the upper end serves as a guide for the operator in positioning and assembling the exhaust tube 49. For example, with the clamps26, 31 open for the reception of an exhaust tube, the guide 62 should occupy a position either in line with the clamtps 31 and 41 or closely adjacent thereto, pre erably the former in which case the guide may be adjusted to define the position of the upper end of the tube 49 abutting thereagainst. The burner 24 directs a flame down into or against the upper end of the exhaust tube to expand the air therewithin and blow out an aperture 63 at the point Where the laterally bent end 50 of the exhausttube is fused to the side of the stem tube. The glass being soft or plastic at this moment and at the weld between the two tubes a comparatively low pressure is sufficient to blow out the hole 63. The flame from the burner 24 may either play upon the previously closed end of the exhaust tube 49 or it may be directed into an open end, as is desired. The guide 62 occupies a position out of line with the flame from the burner 24 during this operation, and if the movement of the rod 28 in closing the clamps 26, 31 is not sufficient for this purpose, the guide may be mounted for movement independently of the rod 28. The laterally bent non-alined tube 50 having been fused to the side of the stem tube 51 and the exhaust hole 63 blown out in position E, the next intermittent movement of the frame 2 carries the rotating spindle to the position h where a single'flame or set of flames 64 is caused to play upon the lower end of the stem tube 51 and thereby permit a slow cooling thereof. At the next intermittent movement the head is carried to position A where by manipulating the handle 27 the operator may simultaneous- 1y unclamp the clamps 26 and 31 and move them out of the way and then by manipulating the gripping parts 43 the clamps 41 may be separated to permit the withdrawal of the completed stem. If the exhaust tube 49 has its outer end closed, either before or during the step of blowing out the hole 63, it of course can be opened by cutting off the closed end in the usual manner.

In Fig. 8 I have shown the burner 24 disposed in a position to direct a heating flame against the side of the exhaust tube 49 which is closed at the upper end, whereby the air pressure may be raised sufficiently inside the .tube 49 to form the small opening 63 at the weld.

Having thus described my invention, what I claim and desire to protect by Letters Patent is:

1. In a stem making machine an intermittently rotatable frame, a rotatable spindle carried thereby, said spindle including stem tube and leading in wire supports, and a support adapted to suspend an exhaust tube within the stem tube with the end thereof in engagement with the wall of the stem tube, means for intermittently moving said frame to different positions and rotating said spindle in said positions, means for heating and forming a seal between one end of the stem tube and the leading in wires including a heating device disposed at one position of the frame, means also at said position and having a different elevation from the first mentioned device for simultaneously heating a portion of the stem tube in the vicinity of the end of the exhaust tube and butt welding the latter to the stem tube at one of said positions, and means for directing a cooling blast of air within the flared end of the stem while welding the exhaust tube and stem tube together rier thereon for the stem parts including an u exhaust tube, a stem tube and leading in wires, a device for supporting the exhaust tube with the end thereof in engagement with the wall of the stem tube, means for heating and forming a seal between one end of the stem tube and the leading in wires including a heating device disposed at one position of the frame, means also at said position of said frame and disposed at a difierent level from the first mentioned device for heating the stem tube at the point of engagement between the exhaust and stem tubes, and means for simultaneously directing a cooling blast within the open end of the stem tube and heating the air within the exhaust tube while welding the two tubes together.

3. In a stem making machine for radio tubes and the like, an intermittently movable frame capable of assuming successively a number of definite positions, a rotating carrier thereon for the stem parts including an exhaust tube, a stem tube and leading in wires, a device for supporting the exhaust tube with the end thereof in end abutting endifferent elevation from that of the first mentioned heating device for heating the stem tube at the point of engagement between the end of the exhaust tube and the stem tube, and means for forming an opening in the stem tube at the point of juncture with the end of the exhaust tube.

In testimony whereof, I have signed my name to this specification.

- CHARLES EISLER. 

